BGA keeps coming back, help! - Algae

DJKronik57 · 07-26-2010, 06:22 AM

So I'm at the point of pulling out my hair. I've had outbreaks of BGA before, but it always was just a little spot here or there that went away on its own, or if not with Maracyn treatment.

Now, it is everywhere in my 46 gallon and it just keeps coming back. I first beat it back with a Maracyn treatment, following the dosage on the package. But a week or two later, it was back with a vengeance. Then I tried a week blackout. Looked a little weaker, but so did all my plants, and it bounced right back along with them. Finally, I tried a week blackout, followed by a Maracyn treatment, along with hydrogen peroxide spot treatment. I thought I had it licked, and it stayed away for a month, but now it's all over everything all of a sudden. I'm at my wits end and have no idea what's causing it.

What's causing these repeat outbreaks, and is there anything I can do about it?

Stats:
Light - 96 watts 8hrs
Ferts- Pressurized CO2, 4bps; NPK and traces dosed daily (nitrates are never 0)
Circulation - Eheim 2217 plus a powerhead (strong current throughout the tank)

Tex Gal · 07-26-2010, 06:45 AM

It's usually caused by low nitrates. You're probably killing it with the MaracynII but not stopping the root cause. Try upping your nitrates and it should go away on its own.

DJKronik57 · 07-26-2010, 07:57 AM

Quote:

Originally Posted by Tex Gal

It's usually caused by low nitrates. You're probably killing it with the MaracynII but not stopping the root cause. Try upping your nitrates and it should go away on its own.

That's what I thought too, TexGal. But unless my plants are using much more nitrates and my test kit is off, it can't be the nitrates. My nitrates are regularly around 20-30ppm, and I've tried dosing 1.5 teaspoons of KNO3 every day (which should bring the concentration to around 30ppm in one dose), with no impact.

Could it be an imbalance in another fertilizer? Maybe phosphate? Either way, my plants are doing OK, but not growing like weeds, so I suspect something is off.

Oh, and I've also been using Maracyn, not MaracynII, since that's what I've seen recommended for BGA. Is that not true?

Seattle_Aquarist · 07-26-2010, 08:06 AM

Hi Andrew,

I posted this in May, but your situation sounds so much like mine that I thought it might help. It was an article on Cyanobacteria (BGA) that I did for our GSAS newsletter in May.

Quote:

"Last month I mentioned that I had a “dirty little secret”. I explained that I did not bring plants to the March meeting because I have been fighting cyanobacteria, also known as Blue-Green Algae (BGA), in one of my tanks and I didn’t want to share it with others. After six weeks of trying different methods I seem to be making major headway and will share what is succeeding for me.

As I write this it has been exactly one week since I finished treating an outbreak of BGA in my 30 gallon aquarium. I believe it started because I let my nitrates (NO3) get too low and missed a couple of water changes. In addition I hadn’t cleaned my canister filter for several of months so debris had built up and the flow and circulation had dropped in the tank. Any or all of these conditions could have been the cause for my outbreak.

Here how I got rid of it. First I worked on the causes. I cleaned my canister filter and added an airstone (I would have used a Koralia Pump or powerhead if I had one) to increase circulation. I increased my fertilizer dosage to 1/8 teaspoon (tsp) of KNO3 (potassium nitrate) and 1/64 tsp of KH2PO4 (monopotassium phosphate) per 10 gallons daily. Lastly I increased my 33% water changes to twice a week.

Next I went to work on the algae. I siphoned and manually removed as much of the BGA off of the substrate, plants, and hardscape as possible and cleaned the glass. Most of the easy-to-replace plants I threw out. I removed most of the hardscape from the tank, scrubbed it, rinsed it, and put back in place. It was very important to remove as much BGA as possible before doing the next step to minimize oxygen depletion, and fish death, from dying algae.

I treated the BGA with Hydrogen Peroxide 3.0% (stabilized) solution. Hydrogen Peroxide (H2O2) is available at most grocery stores, pharmacies, and drug stores. I also picked up a 10 ml dosing syringe (for oral dosing of medications) at the drug store when I picked up the H2O2.

I always did this part of the treatment when I knew I was going to be around for at least a couple of hours afterwards so I could watch my fish for signs of distress. I only treated the tank after the lights (about 2 WPG compact florescent) had been on for at least two hours so photosynthesis was occurring at its’ maximum in the BGA. I found that the BGA reaction to the treatment was strongest, and fastest, in the areas of the aquarium with the brightest light (and the most photosynthesis).

I turned off my filter about 5 minutes prior to treatment to minimize water movement. I dosed the 3.0% (stabilized) H2O2 at the rate of 1.5 ml per gallon of water volume (my 30 gallon tank has 24 gallons of water in it). I put the H2O2 in a glass, filled the 10 ml syringe, stuck my hand in the tank, and s-l-o-w-l-y “painted” the areas where the BGA was heaviest with the thickest “clumps”. I added the H2O2 at a rate of about 10 ml per minute so as not to stress the fish too greatly.

The effect was rapid and dramatic. After several of minutes the areas of BGA I had “painted” with the H2O2 began to bubble (gas) and started to turn a rusty brown. After about 30 minutes the “painted” areas were bubbling intensely and had turned a definite brown color while other areas of the tank (where I had not “painted”) were also bubbling (but not as intensely) and starting to turn rusty brown. After about an hour the water in the tank had a slight “rusty” color, the areas or BGA I had “painted” were a definite brown, areas of BGA that were heavy but had not been “painted” had some of the brown, and plant leaves that had a film of BGA and a film of brown. After one hour I turned the filter and airstone back on and continued to observe the fish for any signs of distress for an additional hour. After a couple of hours the water cleared and the fish become more active. After 24 hours the areas I had "shot" had turned a grey color and the BGA appeared dead.

I followed the same procedure for dosing the next day again dosing the areas with heaviest algae that was yet dead. The dosed areas bubbled and turned rusty but there was not as much bubbling and rust in other areas (I think because areas with a light coating of BGA had been killed on the first day), the water did not changed color as much, and bubbling activity and any discoloration cleared in about 2 hours.

Each day for a two week period I followed the procedure I described above. Each day the amount of BGA diminished and after about 8 days the BGA appeared to be gone. I continued the treatment for an additional four (4) days just to be sure there was no residual “hiding” in the crevasses of my driftwood or under plant leaves. It was not necessary to hit the BGA directly with the hydrogen peroxide to kill it. For example, on the edges and undersides of plant leaves I did not “paint” the areas but after about 5 days the BGA had turned rusty brown, was breaking away from the leaves, and was falling off.

As a side note I also had an outbreak of Black Brush Algae (BBA) in this same tank; probably due to the low CO2. The treatment described above worked on it as well, but the BBA did have to be “painted” to die and areas in bright light responded the best to treatment."

I hope this information helps you. Since May I have had just one situation where the BGA tried to re-establish itself (when I missed fert dosing for a few days) and I followed the above procedure (clean filter; increase fert dosing; increase water changes; treat with H2O2) and it was gone in two days.

Keep us posted as to your progress!

DJKronik57 · 07-26-2010, 09:35 AM

Quote:

Originally Posted by Seattle_Aquarist

Hi Andrew,
I increased my fertilizer dosage to 1/8 teaspoon (tsp) of KNO3 (potassium nitrate) and 1/64 tsp of KH2PO4 (monopotassium phosphate) per 10 gallons daily.

Wow, that's 2 tablespoons of KNO3 per day, and 1/4 tablespoon of KH2PO4 per day!! Is an overdose of nitrates going to put my fish at risk? Just worried about dumping this much into the tank, seeing as the most I've ever done before was less than a quarter of that dose.

EDIT: Never mind, missed the "per 10 gallon" part! Unfortunately, that's currently less than what I'm currently dosing. I'll try doing another water change during the week and cleaning out my canister filter again though. I also noticed that my BGA doesn't seem to react to H202. It bubbles, but it seems to be fine afterwards unless I manage to get the H202 under the "skin."

Seattle_Aquarist · 07-26-2010, 10:17 AM

Hi Andrew,

I think several things aided my success: I turned off all water circulation 5 minutes prior to dosing H2O2 and did not re-start the circulation/filtration for 30 minutes; I "shot" the H2O2 directly onto the BGA with the syringe and without the circulation the H2O2 stayed in contact with the BGA longer; and I dosed after the lights had been on for a least 2 hours to insure the BGA was at maximum photosynthesis (this is a key to success based upon articles I read on treating Cyanobacteria in sewage treatment plants). I tried the Maracyn treatment with minimal success.

BTW, I dose the 1/8 tsp. KNO3 and 1/64th tsp KH2PO4 per 10 gallons as my daily dosing level now and have not seen any BGA for 6 weeks.

houseofcards · 07-26-2010, 01:45 PM

If it was my tank and the KNO3 increase didn't help I would do everything to make your water as clean (low organic) as possible. I have never met an algae or BGA that liked clean water. I would remove as much as you can with a filter hose, do a big water change, clean out your filter and add organic removal products (Purigen/carbon, the kitchen sink) anything that will remove organics from the water in tandem with less feeding, etc. Do a few more manual removal/WC during the week and see where you are.

Newt · 07-26-2010, 04:13 PM

BGA101:
- Polluted water - organics too high>>>water changes, find source and correct
- Dirty filter or under filtered>>>clean filter(s), increase filtration, do regular maintenance
- low nitrates>>>dose KNO3 and maintain minimum 10ppm, 20 to 30ppm even better
- very high phosphate>>>lower PO4 levels, see if anything is contributing to high levels and correct
- lighting spectrum too high in the 550nm - 600nm range or old bulbs>>>change bulbs

Tex Gal · 07-26-2010, 06:15 PM

I'm sorry, it is Maracyn not Maracyn II. Sounds like you have lots of good advice.

Newt · 07-26-2010, 07:22 PM

I forgot to provide my typical BGA warning: BGA is an hepatotoxin (liver) take caution not to splash water into mouth or eyes. Maintain good hygiene. It is better to handle affected plants with tongs and not bare hands.